How Do You Clean a Velux Window From the Inside?

Trade people call the glazed leaf that swings inside the fixed frame the sash. On a pivoting roof window it swings on a horizontal axis, so you can lift the bottom edge and turn the whole sash over until the outer pane faces into the room. That is the trick that lets you wash the weather side without stepping outside.

Start by opening the window a little and wiping down the inner pane while it is still in its normal position. Then push the sash upwards and over. As it rotates, it should stop and hold itself in the cleaning position, with the outer glass facing you at about waist or chest height. A lock or catch on the sash does that job, and it is the part to check first if your window will not stay turned. Work with the sash secured, because a sash that swings back while your arm is across it can trap fingers.

Top-hung and centre-pivot designs differ, so the manual for your model is the best guide to how far the sash turns. If the paperwork has gone, the model label on the frame tells you what you have.

A bowl of warm water with a little detergent, a sponge, and a squeegee or dry microfibre cloth to finish will lift ordinary grime. Glass on a sloping roof collects pollen, bird droppings and the green film that grows where rain runs slowly, so a second pass with clean water stops streaks drying on.

Avoid abrasive pads, scrapers and strong solvents. Modern roof glass often carries a coating on its surfaces, and scratches or harsh chemicals can mark it. Keep pressure washers away from the frame and seals, because the water can be forced past gaskets that are built only to shed rain.

Wipe the frame, the gasket around the sash and the tracks of any blind while you are there. Debris in the seal stops the window closing evenly. A small brush clears the drainage slots along the bottom of the frame, which can clog with grit and leaves. Leave the sash open to air for a few minutes before you turn it back and close it firmly.

If the glass looks misted between the panes, that is a failed sealed unit, not dirt, and washing will not clear it. Our answer on replacement glass for Velux windows explains what can be swapped without replacing the whole frame.

A window set high on a stair landing or over a stairwell is the usual problem. The answer is to bring the cleaning to you. A long-handled extension pole with a pad on the end lets you wipe the inner pane from the floor, and many people flip the sash only when they can stand on a firm, level surface at a comfortable height.

Do not lean over a stair or a landing rail, and do not balance on a chair, a bath edge or the top of a stepladder in front of the window. A fall indoors is still a fall. If the only way to the glass is a precarious stretch, leave it. Tell us the height and the room layout, and we can say whether a lower position, a lever-operated opener or a different window type would help.

Never climb onto the roof to clean the outside. Wet tiles and moss are slippery, and the glass itself is not a safe place to put a foot. If a blocked outer pane is the real concern, that outer face needs a roofer who can get onto the roof properly. Our roof windows and skylights page covers the wider range of work we do.

There is no set interval. Roof glass shows the dirt sooner than wall windows, because rain does not run cleanly off a shallow slope, so a wash in spring and another in autumn, with an extra one after leaf fall if a tree overhangs the roof, keeps the view clear. A window that is shaded by a neighbouring roof will collect algae more quickly than one in full sun.

Cleaning also gives you a regular look at the seals and the flashing, the metal or lead strips that make the join between the frame and the tiles weatherproof. Check them for gaps, lifted edges or stained plaster underneath. If the sash will not turn, will not lock in the cleaning position or sticks along one side, the hinge or the frame may have shifted. Water stains on the lining are a different matter and point towards a fault in the weathering; see why a Velux window leaks for the usual causes.

Condensation on the inside face is common in a damp room and is not a sign of a failed window. Wipe it away, ventilate the room and look at our answer on condensation on a Velux window if it keeps returning.